Impedance relay



Feb. 16, 1932. H HErrMAN 1,845,269

IMPEDANCE RELAY Filed May 8, 1929 Patented Feb. 16, 1932 UNITED STATES PATENT OFFICE HERBERT T. HEITMAN, F DREXEL HILL, PENNSYLVANIA IMPEDANCE RELAY Application led Hay 8, 1929. Serial No. 361,364.

between the plungers and cores which facilitates and makes certain the operation of the device. Another object of the'invention is to provide for varying the air gap thus assisting the making of calibrations. Another object of the invention is to provide for ready inspection without dismantling the relays thereby shortening the time required for inspecting and testing. Another obj ect of the invention is to prevent the plungers from seating on the coil cores thus doing away with their becoming sealed together as they tend to do in known relays in which by sealing they prevent the potential elements from operating when a fault occurs.

Other objects of the invention will appear from the following description at the end of which the invention will be claimed.

To these and other ends hereinafter set forth the invention, generally stated, may be said to comprise an impedance relay having a coil, a coil core projecting into the coil, and a plunger and in association therewith means for providing an air gap between the bottom of the. plunger and the top of the coil core thereby preventing freezing or sealing together of said parts and insuring operation of the potential elements. Further the invention comprises means of the character last referred to including a guide pin extending from the plunger through the bushing or coil core, a slateoid disk for the guide pin to rest on, a mounting stud for the disk, and a check nut to lock the disk in any desired position.

The invention further comprises the improvements to be presently described and finally claimed.

In the following description reference will be made to the accompanying drawings forming part hereof and in which Figure 1 is a diagrammatic view, somewhat in perspective, of an impedance relay embodying features of the invention, and

Fig. 2 is -a view, principally in central section, drawn to an enlarged scale and illustrating' features of the invention.

In the drawings there has been selected as an instrument in which to illustrate an embodiment of the invention a CZ impedance relay manufactured by the Vestinghouse Electric Se Manufacturing Company. 1 is the coil core and it is shown in the form of a bushing extending into the hollow of the coil 2. 3 is the plunger, and the plunger and the coil core are usually of steel. 4 is a pin or projection extending from the plunger 3 through the bushing or coil core 1, and outside of and below the coil. 2. 5 is a disk for the guide pin or extension 4 to rest upon. This disk 5 is of material such as stone and good results have been obtained by making it of slateoid, which is an article of trade that can be bought under that name. 6 is a threaded stud upon which the disk 5 is connection so that the air gap between the top of the coil core l and the bottom of the plunger 3, indicated upon the drawings at a, may be adjusted, but the presence of that air gap at a is an important feature of the invention because it prevents the plunger and the coil core from adhering together as they frequently do now in practice. The end of the pin or projection f1 does not adhere to the disk 5, and it is my best information that the location of the contact between them outside of the coil and coil core as well as the character of material employed for the disk 5 are important factors in the attainment of that result.

While impedance relays are well understood it may be helpful to say that the coil 2 is a potential coil normally operative to move the pin or extension 4 against the disk 5 with the result that the beam 7 pivoted to a horizontal pivot 8 permits the contact 9 to remain open. The Contact 9 controls a circuit 10 which operates to open circuit breakers, not shown and too well understood to require illustration. 11 is a current coil which operates in case of a fault through the core 12 to turn the disk 13 in the direction indicated by the arrow. 14 is a dampening magnet. Vhen the voltage in the coil 2 drops, the cur` rent coil 11 causes the disk 18 to turn in the mounted by a threaded Cil direction indicated by the arrow about vertical pivots 15. One end of the spring 16 is connected with the disk and the other end is Y connected with an arm 17 rigid with and depending rom the beam 7 so that as the disk turns the beam is tilted closing the contacts 9. There is nothing particularly new about the operation and parts last described but by the present invention the beam 7 is always free to turn, when a fault occurs andthe voltage in the coil 2 falls, into position for closing the contacts 9, because the plunger 3 is free to move and does not adhere to the part'by which it is supported, or more speccally, the pin or extension l does'notadhere to the disk 5, and the air gap a prevents the plunger from adhering to the coil core l.

lt will be obvious to those skilled in the artr to which the invention relates that modilications may be made in details of construction and arrangement and matters of mereV form :without departing from the spirit of the invention which is not limited to such matters or otherwise than the prior art and the appended claims may require.

l claim: l. In an impedance relay having a'coil and a coil Ycore projecting into the coil and a plunger in combination therewith means for providing an air gap between the bottom of the plunger and the top of the coil core thereby preventing freezing of said parts, said means including a guide pin extending 'from the plunger through the coil core and. beyond the same, a slateoid disk for the guide pin to rest on, a mounting stud for the disk, and a check nut to lock the disk in any desired position. Y

2. An impedance relay comprising in combination, Va coil, a coil coreprojecting upwardly into said coil, a plunger' within said coil and above said coil core with an air gap between the coil core and the plunger, a guide pin projecting downward from the end of said plunger, a support of hard insulating material beneath said plunger' directly supporting therend of the plunger, and means for adjusting the height of said support and thereby regulating said air gap.

3. An impedance relay including a coil, a coil core cooperating with said coil, a plunger ycooperating with said coil core and with said coil and spaced from said coil core with an air gap therebetween, and a direct nonresilient support for said coil corel regulating the minimum distance of said air gap, said support including a member of insulating hard non-inductive material.

HERBERT T. HEITMAN. 

